9531745 Wobbe Turnip crinkle virus, a plant pathogen, has been shown to require two small proteins for movement and systemic infection in plants. Characterization of the proteins will be continued by site-directed mutagensis coupled with functional characterization of such mutants. Deletion analysis will be used to determine regions of the protein which are necessary for nucleic acid binding and cooperatively. An attempt will be made to separate the two functional domains. Work will also continue with the TCV mutant which does not induce the hypersensitive response in certain plants although it replicates and spreads as does wildtype. %%% Plant viruses are among the best defined plant pathogens; they have small genomes and are easily genetically manipulated. The question of how they move through the plant in the course of systemic infection is important to understand and this work should add to our knowledge of that process. ***